1. /* ====================================================================

  2.  * The Apache Software License, Version 1.1

  3.  *

  4.  * Copyright (c) 2002-2003 The Apache Software Foundation.  All rights

  5.  * reserved.

  6.  *

  7.  * Redistribution and use in source and binary forms, with or without

  8.  * modification, are permitted provided that the following conditions

  9.  * are met:

  10.  *

  11.  * 1. Redistributions of source code must retain the above copyright

  12.  *    notice, this list of conditions and the following disclaimer.

  13.  *

  14.  * 2. Redistributions in binary form must reproduce the above copyright

  15.  *    notice, this list of conditions and the following disclaimer in

  16.  *    the documentation and/or other materials provided with the

  17.  *    distribution.

  18.  *

  19.  * 3. The end-user documentation included with the redistribution, if

  20.  *    any, must include the following acknowledgement:

  21.  *       "This product includes software developed by the

  22.  *        Apache Software Foundation (http://www.apache.org/)."

  23.  *    Alternately, this acknowledgement may appear in the software itself,

  24.  *    if and wherever such third-party acknowledgements normally appear.

  25.  *

  26.  * 4. The names "The Jakarta Project", "Commons", and "Apache Software

  27.  *    Foundation" must not be used to endorse or promote products derived

  28.  *    from this software without prior written permission. For written

  29.  *    permission, please contact apache@apache.org.

  30.  *

  31.  * 5. Products derived from this software may not be called "Apache"

  32.  *    nor may "Apache" appear in their names without prior written

  33.  *    permission of the Apache Software Foundation.

  34.  *

  35.  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED

  36.  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

  37.  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

  38.  * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR

  39.  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

  40.  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

  41.  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

  42.  * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

  43.  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,

  44.  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT

  45.  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

  46.  * SUCH DAMAGE.

  47.  * ====================================================================

  48.  *

  49.  * This software consists of voluntary contributions made by many

  50.  * individuals on behalf of the Apache Software Foundation.  For more

  51.  * information on the Apache Software Foundation, please see

  52.  * <http://www.apache.org/>.

  53.  */

  54. package org.apache.commons.lang.exception;

  55. 

  56. import java.io.PrintStream;

  57. import java.io.PrintWriter;

  58. 

  59. /**

  60.  * An interface to be implemented by {@link java.lang.Throwable}

  61.  * extensions which would like to be able to nest root exceptions

  62.  * inside themselves.

  63.  *

  64.  * @author <a href="mailto:dlr@collab.net">Daniel Rall</a>

  65.  * @author <a href="mailto:knielsen@apache.org">Kasper Nielsen</a>

  66.  * @author <a href="mailto:steven@caswell.name">Steven Caswell</a>

  67.  * @author Pete Gieser

  68.  * @since 1.0

  69.  * @version $Id: Nestable.java,v 1.9 2003/08/18 02:22:24 bayard Exp $

  70.  */

  71. public interface Nestable {

  72.     

  73.     /**

  74.      * Returns the reference to the exception or error that caused the

  75.      * exception implementing the <code>Nestable</code> to be thrown.

  76.      *

  77.      * @return throwable that caused the original exception

  78.      */

  79.     public Throwable getCause();

  80. 

  81.     /**

  82.      * Returns the error message of this and any nested

  83.      * <code>Throwable</code>.

  84.      *

  85.      * @return the error message

  86.      */

  87.     public String getMessage();

  88. 

  89.     /**

  90.      * Returns the error message of the <code>Throwable</code> in the chain

  91.      * of <code>Throwable</code>s at the specified index, numbererd from 0.

  92.      *

  93.      * @param index the index of the <code>Throwable</code> in the chain of

  94.      * <code>Throwable</code>s

  95.      * @return the error message, or null if the <code>Throwable</code> at the

  96.      * specified index in the chain does not contain a message

  97.      * @throws IndexOutOfBoundsException if the <code>index</code> argument is

  98.      * negative or not less than the count of <code>Throwable</code>s in the

  99.      * chain

  100.      */

  101.     public String getMessage(int index);

  102. 

  103.     /**

  104.      * Returns the error message of this and any nested <code>Throwable</code>s

  105.      * in an array of Strings, one element for each message. Any

  106.      * <code>Throwable</code> not containing a message is represented in the

  107.      * array by a null. This has the effect of cause the length of the returned

  108.      * array to be equal to the result of the {@link #getThrowableCount()}

  109.      * operation.

  110.      *

  111.      * @return the error messages

  112.      */

  113.     public String[] getMessages();

  114. 

  115.     /**

  116.      * Returns the <code>Throwable</code> in the chain of

  117.      * <code>Throwable</code>s at the specified index, numbererd from 0.

  118.      *

  119.      * @param index the index, numbered from 0, of the <code>Throwable</code> in

  120.      * the chain of <code>Throwable</code>s

  121.      * @return the <code>Throwable</code>

  122.      * @throws IndexOutOfBoundsException if the <code>index</code> argument is

  123.      * negative or not less than the count of <code>Throwable</code>s in the

  124.      * chain

  125.      */

  126.     public Throwable getThrowable(int index);

  127. 

  128.     /**

  129.      * Returns the number of nested <code>Throwable</code>s represented by

  130.      * this <code>Nestable</code>, including this <code>Nestable</code>.

  131.      *

  132.      * @return the throwable count

  133.      */

  134.     public int getThrowableCount();

  135. 

  136.     /**

  137.      * Returns this <code>Nestable</code> and any nested <code>Throwable</code>s

  138.      * in an array of <code>Throwable</code>s, one element for each

  139.      * <code>Throwable</code>.

  140.      *

  141.      * @return the <code>Throwable</code>s

  142.      */

  143.     public Throwable[] getThrowables();

  144. 

  145.     /**

  146.      * Returns the index, numbered from 0, of the first occurrence of the

  147.      * specified type in the chain of <code>Throwable</code>s, or -1 if the

  148.      * specified type is not found in the chain.

  149.      *

  150.      * @param type <code>Class</code> to be found

  151.      * @return index of the first occurrence of the type in the chain, or -1 if

  152.      * the type is not found

  153.      */

  154.     public int indexOfThrowable(Class type);

  155. 

  156.     /**

  157.      * Returns the index, numbered from 0, of the first <code>Throwable</code>

  158.      * that matches the specified type in the chain of <code>Throwable</code>s

  159.      * with an index greater than or equal to the specified index, or -1 if

  160.      * the type is not found.

  161.      *

  162.      * @param type <code>Class</code> to be found

  163.      * @param fromIndex the index, numbered from 0, of the starting position in

  164.      * the chain to be searched

  165.      * @return index of the first occurrence of the type in the chain, or -1 if

  166.      * the type is not found

  167.      * @throws IndexOutOfBoundsException if the <code>fromIndex</code> argument

  168.      * is negative or not less than the count of <code>Throwable</code>s in the

  169.      * chain

  170.      */

  171.     public int indexOfThrowable(Class type, int fromIndex);

  172. 

  173.     /**

  174.      * Prints the stack trace of this exception to the specified print

  175.      * writer.  Includes information from the exception, if any,

  176.      * which caused this exception.

  177.      *

  178.      * @param out <code>PrintWriter</code> to use for output.

  179.      */

  180.     public void printStackTrace(PrintWriter out);

  181. 

  182.     /**

  183.      * Prints the stack trace of this exception to the specified print

  184.      * stream.  Includes inforamation from the exception, if any,

  185.      * which caused this exception.

  186.      *

  187.      * @param out <code>PrintStream</code> to use for output.

  188.      */

  189.     public void printStackTrace(PrintStream out);

  190. 

  191.     /**

  192.      * Prints the stack trace for this exception only--root cause not

  193.      * included--using the provided writer.  Used by {@link

  194.      * org.apache.commons.lang.exception.NestableDelegate} to write

  195.      * individual stack traces to a buffer.  The implementation of

  196.      * this method should call

  197.      * <code>super.printStackTrace(out);</code> in most cases.

  198.      *

  199.      * @param out The writer to use.

  200.      */

  201.     public void printPartialStackTrace(PrintWriter out);

  202.     

  203. }